Fix: This Blu-ray Disc Needs a Library for AACS Decoding and your system does not have it

Blu-ray was the best quality one can stream movies back at the beginning of this century. Today, we have even better video quality but there are groups of people who prefer watching Blu-ray-quality movies.    

This Blu-Ray Disc Needs A Library For AACS Decoding And Your System Does Not Have It

When these people try to play blu-ray movies through a well-equipped video player such as the VLC media player, there are chances that they see the error named “This Blu-ray Disc needs a library for AACS decoding and your System does not have it.” If you have experienced this error message and are unable to watch the movie, this article will help you proceed with your watch party. Grab some popcorn! We got you. 

When Do I Face The ‘Blu-ray Disc Needs A Library For AACS Decoding’ Error Message In The VLC Media Player?

The Blu-ray disc needs a library for AACS decoding errors that show up on your screen when the VLC media player is used to play a Blu-ray format (H. 264) video file on your computer.  This issue can take place on computers that run on all the recent versions of the Windows Operating System (OS), including Windows 7, Windows 8, and Windows 10. It can also appear on almost every VLC media player version. 

What is AACS?

The Advanced Access Content System (AACS) is an element of media streaming tools and platforms that is set as a standard measure for release license management for media content like movies, especially launched through Blu-ray.

It is a mode of security that prevents the copying of the contents of a Blu-ray optical disc, by restricting access to it. This is done to avoid piracy and illegal distribution of the movie. 

There are two important files that will come up while trying to fix the Blu-ray disc AACS error message on your computer. 

Libaacs.dll: This is the AACS decoding file.

KeyDB.cfg: This file is a constituent of the AACS Dynamic library section.

Note: Restricting access is not to be confused with encryption, which can allow entities to access the files after using a bypass key or with a de-encryption operation. 

Factors That Cause The Blu-ray Disc Needs A Library For AACS Decoding Error on your VLC Media Player

There are two major influential factors that can cause the Blu-ray Disc to need a library for AACS decoding VLC Media Player error when a Blu-ray disc is attempted to be played on your Windows computer.

The following are the two reasons that can cause this Blu-ray error – 

  1. The Blu-ray disc is secured by the AACS and/or BD+ technology.

The AACS encryption tool could be protecting the contents of the Blu-ray disk to prevent illegal distribution. The VLC media player fails to play the movie as the libbluray library could be insufficient for running the Blu-ray discs. 

  1. The KeyDB.cfg file cannot be detected on your computer. 

The Keys Database cfg file (KeyDB.cfg) is an important file that is required for the libaacs library. This library is essential for the buffering of the Blu-ray video files on the encrypted Blu-ray discs. 

Fixing The AACS Decoding Error

There are two steps involved in the process of trying to overcome the Blu-ray DVD disc that needs a library for AACS decoding VLC media player error on your computer. You will have to – 

  1. Add the AACS into the AACS decoding library
  2. Place the libaacs.dll in the VLC Installation folder

We have divided these processes into two parts since they are quite elaborate and can be quite long when put assembled together as one.  

Part 1: Inserting The AACS With Library Files

The first part of the Blu-ray disc needs a library for AACS decoding fix is to make a new library for AACS and place the keys database in the newly created AACS folder. Here are the steps to add libraries files to 

  1. Download the Keys Database and the AACS Dynamic library onto your computer through the file link. The website might warn you of an absent SSL certificate. Also, there are different versions of the VLV media player so you will have to download the 64-bit or 32-bit OS version.
Keys Database and AACS Dynamic library files in the Downloads folder
  1. After the download is complete,  copy the KeyDB.cfg file from the download folder to your clipboard (Ctrl + C).
  2. Then, launch the Run tool (Windows + R) and enter this location in the Open field:


%APPDATA% command in the Run utility

The AppData folder is usually hidden. One way to access the hidden AppData folder is through the Run tool.

  1. Create a new folder and name it AACS. 
Creating a new AACS folder in the %APPDATA% directory

You can make a new folder with the help of the New Folder icon or the context menu. 

  1. Now, paste the KeyDG.cfg file into the newly created AACS folder. 
KeyDB.cfg file in the new AACS folder

Part 2: Placing The Libaacs.dll In The VLC Install location

The second part of fixing the Blu-ray disc needs a libaacs library for AACS decoding error messages on your computer, which involves having to put the required library files in the VLC media player’s 

  1. Bring up the download folder window again and, now, copy the libnaacs.dll file onto your clipboard. 
  2. Then, open File Explorer (Press Windows + X) and go to this directory:

C:\Program Files\VideoLAN\VLC

VLC installed folder in the Windows Program Files

If you cannot find the VideoLAN folder here, check this location:

C:\Program Files(x86)\VideoLAN\VLC

These are the default location of the VLC media player files. 

  1. Place the libaacs.dll file in this location and then, launch the VLC media player and play your Blu-ray disk to see if the window runs without any issues. 

These are the methods to play Blu-ray disc files on your computer, without facing the Blu-ray disc needs a library for AACS decoding issue on your Windows 10 computer. You will now be able to play Blu-ray disks on any VLC version, without facing these Blu-ray errors on your computer.